A mass flow verifier (MFV) may be used to verify the accuracy of high-precision fluid delivery systems such as mass flow controllers (MFCs) and mass flow ratio controllers (FRCs). Typically, a mass flow verifier may include a chamber, a pressure transducer, a temperature sensor and two isolation valves, one upstream and one downstream. The valves may be closed during idle, and may open when a run is initiated, allowing flow of fluid from the device under test (DUT) such as a MFC or a FRC through the flow verifier. Once fluid flow has stabilized, the downstream valve may be closed, and as a result the pressure may rise in the chamber, and the raise in pressure may be measured as well the gas temperature. These measurements may be used to calculate the flow rate and thereby verify the performance of the DUT.
A mass flow delivery device, such as a Mole Delivery Device (MDD), may be used to accurately deliver desired amounts of gases into semiconductor processing chambers. Such mass flow delivery devices may provide highly repeatable and precise quantities of gaseous mass for use in semiconductor manufacturing processes, for example atomic layer deposition (ALD) processes.
In the last few years cost reduction initiatives for semiconductor processing tools have had a significant impact on the design of the fluid delivery systems, by streamlining the design and reducing foot print. While the size and complexity of the fluid delivery systems have been reduced, the need for verification and precision of the delivery has increased.
Both features, i.e. mass flow delivery and mass flow verification, are necessary due to the increased requirement for flow accuracy as well as the delivery of critical fluid(s) into the process chambers. The cost to customers for owning both a MFV and a MDD, however, is expensive and onerous. Also, MDDs tend to have a large footprint.
Accordingly, there is a need for systems and methods that would provide customers a cost effective solution to the requirements of both mass flow verification and mass flow delivery.